Still scraper



E. CRAVENS STILL SCRAPER Nov. 11 1924.

Filed Feb. 5, 1922 2 Sheets-Sheet 1 5 E. Craven- .NVENTQR ATTO RN EYWITNESSES 'Nov. 11 1924- E. CRAVENS STILL SCRAPER Filed Feb. 5, 192?. 2Sheets-Sheet 2 INVENTOR ATTO R N EY WITNESSES Patents Nov. ll, 12 3-.

ETHURGE CRAVE-NS, OF WEST TULSA, OKLAHOMA.

STILL scnarnn.

Application filed February 8, 1922. Serial No. 538,879.

To all whom it may concern:

Be it known that I, Errr'uaon (humans, a citizen of the United States,residing at West Tulsa, in the county of Tulsa and State of Oklahoma,have invented new and useful Improvements in Still Scrapers, of whichthe following is a specification.

This invention relates to attachments for stills used in refining oiland has for its object the rovision of a continually acting power drivenscrapii g mechanism forming a permanent part of the still and operatingto eliminate the accumulation of carbon deposits and consequentlyprevent hot spots which result in causing buckling of the still, thedevice further operating to greatly increase the utility of the still inmaking it capable of longer use before taking down and hand cleaning isnecessary.

It is well in the art that in the operation of stills either of thepressure or vacuum type used in refining oil, carbon deposits accumulateon the wall of the still and result in the formation of what is known ashot spots which cause the stills to buckle and make it necessary to shutdown the still and make repairs with a considerable expenditure of timeand labor. It is also well known that various types of mechanicaldevices which might be conceived would not operate in a still of thischaracter owing to the presence of the carbon which would causedisintegration of the parts of many mechanical devices it an attemptwere made to use them. With these facts in view I have designed thepresent device which has for an important object the provision of aconstantly rotating device within the still carrying a plurality ofscraper blades which are gravity operated and which engage against thestill walls and scrape off the carbon deposit as it is formed, thedevicebeing furthermore of a spiral nature whereby to move all thesediment to the rear end of the still where the major portion of thesediment and carbon may be drawn ofi' subsequently.

An additional object is the provision of a mechanism of this characterwhich will be simple and inexpensive in manufacture and installation, hihly efiicient in use, positive in action, duralfle in service and ageneral improvement in the art.

With the above and other objects and advantages in view, the inventionconsists in the details of construction to be hereinafter more fullydescribed and claimed, and illustrated in the accompanying drawings inwhich, a

Figure 1 is a longitudinal sectional view taken through a still andshowing a side elevation of my device in applied position therein.

Figure 2 is a cross-sectional view through the still and showing an endview of my device. a

Figure 3 is a perspective view, on a larger scale, of a portion of thespiral support and showing a view of the scraper associated therewithand Figure 4 is a detail perspective view of one of the scraper devices.

Figure 5 is a detail perspective view of one of the bearing bracket-s.

Figure 6 is a detail perspective view of the pivot member carried by thearm of the scraper device, and

Figure 7 is adetail cross sectional view through the bearing member andthe pivoted end of the scraper device.

Referring more particularly to the drawings the letter A designates aconventional still such as used in oil refinin this still being mountedupon the usual Iarick work B which defines a fire-box C. The still isprovided at its top with a vapor outlet G and in the lower part of oneend with a tar outlet pipe E provided with a cut-off valve F.

In carrying out my invention I provide a shaft 10 which is journaledlongitudinally of the still A and which is supportedby suitable bearings11 provided on the lower ends of hangers 12 suitably mounted within, anddepending from the top portion of, the still. One end of this shaftprojects through the end wall of the still and carries a gear 13 or thelike by means of which it may be driven. Secured suitably upon the shaft10 and radiating therefrom atdifferent angular positions are supportingspokes 14: which carry a bar 15 wh1ch is of spiral formation and whichextends substantially throughout the length of the still as clearlyshown in Figure 1. The bar 15 maybe of channel iron, angle iron or thelike and must of course be of considerable weight depending upon thesize of the still. Secured at intervals u on the bar 15 are bearingmembers 16 which may be mounted at any desired distance apart owing tothe fact that the bar 15- is formed throughout p which discharges intothe interior of the still and through which steam may be passed for thepurpose of cleaning out the still.

Assuming that the device has been constructed and installed as abovedescribed,

the operation is as follows:

When the shaft 10 is rotated by any desired means, it will be apparentthat the spiral formation of the bar will cause sediment within thestill to be moved rearwardly by the sore er blades. Owin to the factthat these b ades are pivoted, it is a parent that they will drop awayfrom e upper portion of the still but as the bar 15 turns and thescraper members are brought toward the bottom or heated portion of thestill, the beveled edges 21 will engage the wall of the still andoperate to scrape away any carbon deposit practically as soon as itforms in order that there will be no accumulation which could result inthe formation of hot spots with the resultant disadvantage thereof. Theblades are placed at asufiicient angle to cause the sediment to movetoward the rear end and each blade laps over on the surface scraped overby the preceding blade a sufficient distance to take the sedimentanother blade width rearwardly and so on through the length of thestill. The blades falllng against the still and then back against thespiral bar' a will operate not only to keep them free from coke but alsoto prevent the formation of coke on the bar or supports thereof. Inactual practice it is intended that the shaft berotated at a suflicientspeed that every uare inch of the heated surface on the still may bescraped every thirty seconds so as to keep the free carbon emulsified tosuch an extent as to prevent its formation in large masses. Of coursesafter the desired per cent of distillate has been removed from the oiltreated in the still, the residue, that is the tar is pumped out throughthe outlet pipe E provided for the purpose. Then steam can be turned inthrough the pipe 23 and the remainin tar can be let out when thetemperature as lowered. sufiiciently to keep the tar from flashinguponexposure to the air. It is not necessary that every particle of the tarand carbon loosened up by the scraper should be removed as it isbelieved that a certain quantity of tar and sediment remaining in thestill will be absorbed into the fresh charge of more voltaile fuel whichis introduced for the next distillation.

From the foregoing description and a study of the drawings it will be aparent that I have thus provided a simp y constructed and easilyinstalled automatically acting continuously rotating device which willeificiently operate to prevent the formation of carbon deposits within astill It is also to be observed that owing to the efliciency of thedevice there will be a great saving in time and labor effected by itsuse as the necessity for hand cleaning is almost eliminated. Owin to thesimplicity of the construction and t e fewness of the parts it isapparent that there is pactically nothing to get out of order and thatthe device will consequently have a long life and satisfactorily performall the functions for which it is intended.

Having thus described my invention I- claim;

1. A still scraping device comprising a shaft journaled longitudinallyof the still, a plurality of spokes radiating from the shaft, a bar ofspiral formation carried by said spokes and extending substantially thefull length of the still, a plurality of brackets adjustably mounted atintervals upon said bar, and a plurality of arms each pivoted within abracket and carryin transversely arranged weighted scraper b ades.

2. A still scraper comprising a shaft journaled longitudinally within astill, a spirally arranged bar supported from said shaft and extendingsubstantially the full length of the still, a plurality of bearinbrackets mounted upon said bar at space intervals, means for varying theposition of the brackets, arms pivoted within the brackets, transversescraper blades mounted at the outer ends of the arms, and weights at theend portions of the blades for normally maintaining them in a certainposition.

3. A rotary scraping device for oil refining stills, comprising a shaftjournaled longitudinallyof the still, a plurality of spokes radiatingfrom the shaft, a bar of spiral formation carried by said spokes andformed throughout its length with a plurality of holes, bearing membersadjustably mounted upon said spiral bar and held by bolts passingthrough selected ones of said holes, arms pivoted upon said bearingmembers, and weighted scraper blades carried by the free ends of saidarms.

In testimony whereof I afiix my signature.

E'IHURGE CRAVENS.

